HomeworkLib
Question

1. Results of a math standard achievement test when analyzed indicated the scores exhibited a normal...

1. Results of a math standard achievement test when analyzed indicated the scores exhibited a normal distribution. The mean was 620 with standard deviation of 52. (a) Some inquired about the fraction of the test takers achieved at 95% confidence scores greater than 800. Determine that fraction, (b) determine for different math test and 95% confidence the range of scores, but only 24 students took this test. The mean was 73, standard deviation of 11.

math   Statistics-And-Probability   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

1a) Let X be the score in math standard achievement test

X follow Normal distribution

to find P(X> 800)= P(Z> (800-620)/52)

= P(Z> 3.46)

= 0.0003

fraction of test takers who scores greater than 800 is 0.0003

b) 95% confidence inerval for true mean

x ̅ ± zc σ⁄√n

= 73  ± 1.96 * 11/√24

= 73 ± 4.4

= (68.6, 77.4)

note: for 95% CI zc = 1.96

0 0
Add a comment
Know the answer?
Add Answer to:
1. Results of a math standard achievement test when analyzed indicated the scores exhibited a normal...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • An educational testing service designed an achievement test so that the range in student scores would...

    An educational testing service designed an achievement test so that the range in student scores would be greater than 420 points. To determine whether the objective was achieved, the testing service gave the test to a random sample of 30 students and found that the sample mean and variance were 759 and 1943, respectively. Assume the range is 6σ. Test whether the test achieved the desired dispersion in scores.

  • Scores this year for students taking the SAT Math test for the first time are believed...

    Scores this year for students taking the SAT Math test for the first time are believed to be Normally distributed with mean Mi. For students taking the test for the second time, this year's scores are also believed to be Normally distributed, but with a possibly different mean M2. We wish to estimate the difference M2 - Mi. A random sample of the SAT Math scores of 100 students who took the test for the first time this year was...

  • The standard deviation of test scores on a certain achievement test is 11.1. A random sample...

    The standard deviation of test scores on a certain achievement test is 11.1. A random sample of 60 scores on this test had a mean of 75.4. Based on this sample, find a 95% confidence interval for the true mean of all scores. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the lower limit of the 95% confidence interval? What is the upper limit...

  • Question 6 (1 point) Solve the problem. When Scholastic Achievement Test scores (SATs) are sent to...

    Question 6 (1 point) Solve the problem. When Scholastic Achievement Test scores (SATs) are sent to test-takers, the percentiles associated with scores are also given. Suppose a test-taker scored at the 98th percentile on the verbal part of the test and at the 14th percentile on the quantitative part. Interpret these results. This student performed better than 98% of the other test-takers on the verbal part and better than 14% on the quantitative part. @ This student performed better than...

  • (4)Five hundred students from a local high school took a college entrance examination. Historical data from the school record show that the standard deviation of test scores is 40. A random sampl...

    (4)Five hundred students from a local high school took a college entrance examination. Historical data from the school record show that the standard deviation of test scores is 40. A random sample of thirty- six students is taken from the entire population of 500 students. The mean test score for the sample is three hundred eighty. Find (a) 95% confidence interval for the unknown population mean test score. (b) 95% confidence interval for the unknown population mean test score if...

  • 1. A certain standardized test has scores which range from 0 to 500, with decimal scores...

    1. A certain standardized test has scores which range from 0 to 500, with decimal scores possible. Scores on the exam are normally distributed with a mean of 301 and a standard deviation of 42. What proportion of students taking the exam receive a score greater than 366? Round your answer to 4 decimal places. 2.A certain standardized test has scores which range from 0 to 500, with decimal scores possible. Scores on the exam are normally distributed with a...

  • 18. Scores this year on the SAT mathematics test (SAT-M) for students taking the test for...

    18. Scores this year on the SAT mathematics test (SAT-M) for students taking the test for the first time are believed to be Normally distributed with mean 4. For students taking the test for the second time, this year's scores are also believed to be Normally distributed but with a possibly different mean 42. We wish to estimate the difference - A random sample of the SAT-M scores of 100 students who took the test for the first time this...

  • Do students tend to improve their Math SAT scores the second time they take the test?...

    Do students tend to improve their Math SAT scores the second time they take the test? We take a random sample of 100 hundred students who took the test twice. The mean score and the standard deviation of these 100 students on the first try are 500 and 90 respectively; the mean score and the standard deviation of these 100 students on the second try are 530 and 92 respectively. We also examine the change in Math SAT score (second...

  • 1.) The scores for the final exam in Math 2250 is normally distributed with a mean...

    1.) The scores for the final exam in Math 2250 is normally distributed with a mean of 60 and standard deviation of 15. Given that 120 students wrote the final exam, i.) State and test the hypothesis that the mean score is greater than 65 at a 10% level of significance. Include a p-value in your answer. 141 ii.) Construct and interpret 90% confidence level for the mean score. [3] Using the same level of significance, determine how many students...

  • 1. (15) Two samples of girls aged 6 and 7 are with the results shown below....

    1. (15) Two samples of girls aged 6 and 7 are with the results shown below. given the Wide Range Achievement Test, Age 6 Age 7 Sample Size 11 15 Mean Score 42 51 Standard Deviation 8 Construct a 95% confidence interval for the difference in mean scores for the two age groups. (10 pts) a. b. Based on the interval from part A, do the test scores differ between the two age groups? Explain your answer. (5 pts) 1....

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT